In general it is called a "plain" (not to be confused with mathematical plane). If it is an area raised above its surroundings it is a plateau. More types of plains in the link below.
An area of high, flat land is known as a plateau. Some famous plateaus are the Tibetan Plateau, the Colombia Plateau, as well as the Antarctic Plateau.
desert, prairie, beach
Plateu
a plateau.
plateau
a plateau
a broad area of flat or gently rolling land is called a plain.
A large, flat area of land is called a plain.
plateu
plateu
Low lying area with large stretches of land
butte, mesa or plateau
it is called a plateau.
The large, flat center of Mexico is called a plateau. This area is also called the land of many climates because of the constantly changing weather pattern in the area.
A large area of flat land or gently rolling land is a bay... There's the answer!!
A Plateau
a plain
A plain is a large, flat expanse of land characterized by low vegetation, relatively level topography, and few geological features. Plains can be found on every continent and are typically used for agriculture and grazing.